The influence of sodium hypochlorite irrigation on the accuracy of the Root ZX electronic apex locator.

The purpose of this in vitro investigation was to determine whether the presence of sodium hypochlorite influences the accuracy of the Root ZX electronic apex locator. Forty, extracted, human teeth were mounted in an experimental apparatus. After achieving ideal access, working length measurements were obtained using the Root ZX. The canals were flushed with 2.125% sodium hypochlorite and measurements were again made with the electronic apex locator. Before measuring a third time, 5.25% sodium hypochlorite was then administered to each canal. Finally, the tooth was removed from the apparatus and the actual canal length was determined by measuring a file brought to the apical constriction (verified by direct visualization). No significant differences were found between the experimental groups. Overall, Root ZX measurements were within 0.5 mm of the actual length 83% of the time. The results of this study indicate that the Root ZX is not adversely affected by the presence of sodium hypochlorite.